Elymus lanceolatus
Elymus ×cayouetteorum
streambank wheatgrass, streamside wild rye, thick-spike wildrye, thickspike wheatgrass
wildrye
22-130 cm, erect;
nodes glabrous.
to 1 m tall, about 4 mm thick.
often mostly basal, sometimes more evenly distributed;
sheaths glabrous or pubescent;
auricles usually present on the lower leaves, 0.5-1.5 mm;
ligules 0.1-0.5 mm, erose, sometimes ciliolate;
blades 1.5-6 mm wide, generally involute, abaxial surfaces usually glabrous, adaxial surfaces strigose, ribs subequal in size and spacing.
not basally concentrated;
sheaths smooth;
ligules about 0.5 mm, glabrous;
blades 20-30 cm long, about 10 mm wide, both surfaces scabrous.
3.5-26 cm long, 0.5-1 cm wide, erect to slightly nodding, usually with 1 spikelet per node, sometimes with 2 at a few nodes;
internodes 3.5-15 mm long, 0.1-0.8 mm wide, glabrous or hairy.
about 25 cm, lower nodes with 1 spikelet, most middle to upper nodes with 2;
internodes about 18 mm.
8-31 mm, 1.5-3 times longer than the internodes, appressed, with 3-11 florets;
rachillas glabrous or hairy, hairs to 1 mm;
disarticulation above the glumes, beneath each floret.
about 40 mm including the awns, about 20 mm excluding the awns, appressed, with 5-8 florets.
subequal, 5-14 mm long, 1/2 - 3/4 the length of the adjacent lemmas, 0.7-1.3 mm wide, lanceolate, glabrous or hairy, smooth or scabrous, 3-5-veined, flat or weakly, often asymmetrically keeled, keels straight, margins narrow, tapering from the base or from beyond midlength, apices acute to acuminate, sometimes mucronate or shortly awned;
lemmas 7-12 mm, glabrous or hairy, hairs all alike, sometimes scabrous, acute to awn-tipped, awns to 2 mm, straight;
paleas about equal to the lemmas, keels straight below the apices, smooth or scabrous proximally, sometimes hairy, scabrous distally, intercostal region glabrous or with hairs, apices 0.2-0.3 mm wide;
anthers (2.5)3-6 mm.
12-15 mm, not or scarcely indurate, mostly smooth, veins scabrous, awns 3-5 mm;
lemmas about 14 mm, glabrous, awns 18-22 mm, not to moderately divergent;
anthers 1.8-2 mm, indehiscent.
= 28.
Elymus lanceolatus
Elymus ×cayouetteorum
Elymus lanceolatus grows in sand and clay soils and dry to mesic habitats. It is found primarily in the western half of the Flora region, between the coastal mountains and 95° W longitude, with the exception of E. lanceolatus subsp. psammophilus, which extends around the Great Lakes. Three subspecies are recognized, primarily on the basis of their lemma and palea pubescence.
Elymus lanceolatus is primarily outcrossing, and hybridizes with several species of Triticeae. Elymus albicans (p. 334) is thought to be derived from hybridization with the awned phase of Pseudoroegneria spicata (p. 281). Judging from specimens of controlled hybrids, hybridization with E. trachycaulus (p. 321) and unawned plants of P. spicata probably occur, but would be almost impossible to detect without careful observation in the field. Experimental hybrids are partially fertile, and capable of backcrossing to either parent (Dewey 1965, 1967, 1968, 1975, 1976).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Elymus ×cayouetteorum consists of hybrids between E. trachycaulus (p. 321) and E. canadensis (p. 303). The above description is based on the type specimen, which was collected on the Ilets Jeremie, Quebec. It is not known how widespread such hybrids are.
Elymus ×cayouetteorum is an Elymus named hybrid
Elymus is notorious for its ability to hybridize. Most of its interspecific hybrids are partially fertile, permitting introgression between the parents. The descriptions provided below are restricted to the named interspecific hybrids. They should be treated with caution and some skepticism; some are based solely on the type specimen, because little other reliably identified material was available. Moreover, as the descriptions of the non-hybrid species indicate, many other interspecific hybrids exist.
The parentage of all hybrids is best determined in the field. Perennial hybrids, such as those in Elymus, can persist in an area after one or both parents have died out, but the simplest assumption is that both are present. Interspecific hybrids of Elymus that have disarticulating rachises presumably have E. elymoides or E. multisetus as one of their parents.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Lemmas densely hairy, hairs flexible, some 1 mm long or longer | subsp. psammophilus |
1. Lemmas glabrous or with stiff hairs shorter than 1 mm. | → 2 |
2. Lemmas with hairs, not scabrous | subsp. lanceolatus |
2. Lemmas smooth, sometimes scabrous distally, mosdy glabrous, sometimes the lemma margins hairy proximally | subsp. riparius |
BC
OR
WA
CalFlora
Flora NW
IL Wildflowers
MI Flora
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
